1. Field of the Invention
The present invention relates to a mechanical press drive and particularly to a wet clutch/brake unit which utilizes a recirculating flow of press lubricant to access and lubricate the clutch/brake unit.
2. Description of the Related Art
Mechanical presses of the type performing stamping and drawing operations have a conventional configuration including a frame structure with a crown and a bed connected by uprights and a slide supported within the frame for reciprocating movement toward and away from the bed. A crankshaft rotatably disposed within the crown is arranged in driving connection with the slide using a connecting arm assembly. A flywheel assembly rotatably driven by the drive mechanism is selectively connectable with the crankshaft for driving rotation thereof, utilizing a clutch/brake combination to make the driving connection. Such mechanical presses are used in a wide variety of workpiece operations employing a large selection of die sets with the press machine varying substantially in size and available tonnage depending upon the intended use.
The primary apparatus for storing mechanical energy within a press is a flywheel. The flywheel is mounted on the crankshaft and mechanically connected to the press motor such that when the press motor is energized, the mass of the flywheel rotates continuously. The press drive motor replenishes the energy that is lost or transferred from the flywheel during press operations when the clutch engages the flywheel to translate rotary motion of the flywheel to the crankshaft. During engagement of the clutch, the flywheel drops in speed as the press driven parts are brought up to running speed.
Prior wet clutch/brake systems have been used in mechanical presses since they offer the advantage of little or no wear on the plates of the disc stacks and no brake fade. This provides a precise operation of the press and dramatically increases press run time.
Wet clutch/brake units known in the art are generally filled with oil and sealed, whereby no oil enters or leaves the unit unless it is manually removed at a service interval. In these configurations, the flywheel operates as a heat sink.
What is needed in the art is a wet clutch/brake combination which is open to allow a flow of recirculating lubricant to enter and exit the clutch/brake assembly and which provides a larger heat sink. What is additionally needed in the art is a wet clutch/brake combination which does not require an additional lubricant source in the press machine.